My simple DIY build

[nac]

Hi everyone. Thanks for the great site.

Well, after a lot of procrastinating, I built my algae scrubber. It might not be pretty, but I'm happy. I got it done before the end of 2010, but am posting today. Perhaps this is the last build of 2010?

A few pictures are worth a thousand words, so they should describe most of my setup.


[attachment=2:34peiqha]SLR 015small.JPG[/attachment:34peiqha]

[attachment=1:34peiqha]SLR 006small.JPG[/attachment:34peiqha]

[attachment=0:34peiqha]SLR 002small.JPG[/attachment:34peiqha]

I have a 55 gallon tank, currently only has live rock, not even fish yet. The HOB filter is from ebay – rated at 800 gph supposedly. The pump on the bottom of the bucket is a lifeguard quietone 3000 – which is rated just under 600gph at 4' head – and this is currently setup at just over 4' head. So I should have at least 500 gph of flow. For lighting – I currently have two CFLs – a 14 watt and a 19 watt. The screens are 10.5” at the top, and 10” to the water line. They are somewhat V shaped to fit into the bucket. So about 100 sq inches of screen. Two screens sandwiched together. I might decide to up the lighting if needed. The lights are in 1 liter bottles with the bottom cut off.

The biggest pain for the build is the hoses – the feed from the tank is 1 1/4 hose inner diameter from Lowes. The feed back to the tank is 3/4 inner diameter also from Lowes. They were on reels, and both want to stay curved. Pain to work with.

I'm worried about the PVC solvent and cement. After cementing, I waited an hour before installing. I hope none of the solvents or cement leached into the water. I think I flushed all all the parts with tap water before installing, but am not sure.

Here is what I'm happy about with my setup:

Lots of water volume, large screen area. I figure that by having a large screen, large volume of water – I might be able to get by with cleaning the screen less often. I aim to start with weekly cleaning as recommended, and then once it is established try 8 days, 9 days, etc.

I like how I attached the tube to the bucket using two short pieces of rope with knots on the ends. The bucket has a lip – with a small hole cut on the top of the lip, and a slit cut on the lip. One knot is through a small hole on the rim of the bucket – so it can't come through. The other knot is in the slit. If you tug it downward, you can get it out of the slit – but a small paper clamp prevents that from happening. Simple. Quick to disassemble. Yet effective.

I attached the screens to the hose using small holes through which rope is strung. Rope goes around the tube. I “tied” the rope together above the tube using plastic clips Again - simple. Quick to disassemble. Yet effective.

What I still need to do:

I'm worried that the return tube will fill with algae. - it runs right next to the lights. Might wrap it with tape? But I don't want any adhesive on the tape to potentially leach out since the tube will get spashed quite a bit.

I also want to create a reflector to prevent light from shining straight down – to prevent algae from growing in the bottom of the bucket and on the pump. Haven't decided how to make a simple one which will survive getting the occasional splash.

I also want to enclose my wiring better. It is currently wrapped with electrical tape. I feel comfortable working with it – I will always unplug before touching. But in the long run I want to enclose it in a plastic conduit or something, and use silicone to seal connections.

Here is the biggest problem: NOISE and bubbles.

The screen is slightly V shaped because the bucket does not have perfectly vertical sides. So the screen is 10.5” on the top, and about 9.5” at the water line. I thought the water would cascade down the angle of the screen – but some simply falls down from the start of the angle. I can correct it by making less of a V shape – I could get by with about 10” at the water line.

Water feeds into the tube from left to right. More water pours out of the right side – it almost shoots out. Some jets toward the bucket, avoiding the screen altogether. I guess I could have made the slot a little thicker? I haven't read a lot on this site – I don't know if anything recommended how thick the slot should be based on water volume and length of the slot. Since I'm moving 500gph through a 10.5” slot – it needs to be thicker or somehow compensate compared to someone moving 350gph through a 10.5” slot.

I will aim to try to compensate by cutting a small area out of the screen to the left, which might cause a bit extra water to come out of the slot earlier. The screens are 50¢ each so I can experiment. I attached a picture – of how I'll cut the screens.

The slot is opposite the right angle which leads up to the overflow. If the hose were straight, it would work well. But, the hose wants to stay curved – so the slot is not straight down – at an angle of I dunno – 15 degrees. The screen on the back therefore has more water flushing over it than the screen in the front. But the front screen does get a good amount of flow. I will experiment with perhaps only lighting the back screen. And I'll create the slow I described on the front screen first.

Thanks for reading. Any feedback is welcome.

[nac]

A couple more pictures:

Here is a diagram of how I want to cut the slot in the screen to increase water flow:
[attachment=1:377f9zcf]Screen diagram.gif[/attachment:377f9zcf]


Here is a picture of my HOB filter. You can see the air in the tube feeding the bucket. I'm not sure how to eliminate that air. Most of the noise seems to come from the slot where the water pours over the screen. A little is coming from this tube.
[attachment=0:377f9zcf]SLR 017small.JPG[/attachment:377f9zcf]

[SantaMonica]

Perhaps this is the last build of 2010?

I think so. I checked my other sites/threads and there were no other new ones today.


two CFLs -- a 14 watt and a 19 watt.

A bit low for a 10 X 10 inch screen, especially since all the light-power will be concentrated in front of the bulbs, and the outer parts of the screens will not be getting enough. But since it is a low-cost build in a bucket, it will be ok to see how the growth develops. Later if you wanted to maximize it, you would have two bulbs on each side.


Two screens sandwiched together

It's currently recommended that you run only one "layer" of screen, especially with weak light, but you can use what you have for a while and see how it goes.


They [hose] were on reels, and both want to stay curved.

You might try pouring boiling water over the outside of the hose when it is not running; let's you mold the direction of the hose, then hold it in place as it cools down.


I'm worried about the PVC solvent and cement. After cementing, I waited an hour before installing. I hope none of the solvents or cement leached into the water. I think I flushed all all the parts with tap water before installing, but am not sure.

Someone with more plumbing experience could probably give you a better answer.


large screen area. I figure that by having a large screen, large volume of water – I might be able to get by with cleaning the screen less often.

Nope. Always every 7 days. And larger screen area does not do anything without more bulbs and wattage. Only the part of the screen within 4 inches of a bulb does any real filtering. Farther parts just grow a dark covering that actually need cleaning more often in order to keep from blocking the light.


I'm worried that the return tube will fill with algae

Since the tubing is clear, it will get growth on the inside, but it won't clog. It would help to use opaque tubing. You could wrap it with foil.


I also want to create a reflector to prevent light from shining straight down – to prevent algae from growing in the bottom of the bucket and on the pump. Haven't decided how to make a simple one which will survive getting the occasional splash.

You could use a plastic coffee can... and cut out only the part facing the screen (and put a foil reflector on the other half.)


I also want to enclose my wiring better.

Yes you will want to use aquarium-safe silicon instead, for the situation described below.


The screen is slightly V shaped because the bucket does not have perfectly vertical sides.

The best fix to to do another pipe/screen, with a straight vertical cut. And a single layer of screen (with a 1/8 inch slot).


Water feeds into the tube from left to right. More water pours out of the right side -- it almost shoots out.

Because double-layer screens are harder to work with, like this. A more-narrow slot will help, but double layers still have plently of space for excess flow. Again, best fix is a 1/8 slot with a single layer.


I guess I could have made the slot a little thicker?

Thinner.


Since I'm moving 500gph through a 10.5 slot

Is ok for a double-layer screen, but you are seeing some of the difficulty of doubles. Doubles are only more effective if all the drawbacks are taken care of, which nobody usually does.


I will aim to try to compensate by cutting a small area out of the screen to the left

No... re-do the pipe for a single layer.

Overall, good try at adding a bucket-sump for your scrubber. HOB feeds are tricky, so you might read up on how to prevent them from stopping.

The main issue with your current build is going to be spray from the pipe when the growth gets thick. They way you have it now, with no real sump below the bucket, it is going to spray out sidways from the pipe and go onto your floor or wood cabinet. Won't happen for a while... after you stock the tank... but it will happen. And it will usually spray directly at your taped-up electrical, which is why you want silicone instead (you should be able to pour water directly over the bulb/wiring without it causing shorts) . You could lay a sheet of plastic or fine screen over the top of the bucket, but it needs to let the lights vent. And still water would flow down the cover and get outside the bucket. You could also put a "light shield" over the pipe, like some people do, but it's still possible for it to spray out at the ends, again going out of the bucket and onto the floor.

The real solution to "buckets" is to cut a hole in the bucket a few inches below the top, which will lower the pipe down into the bucket. This way, when it sprays sideways, it will hit the sides of the bucket. You usually don't need a lid when you do this.

So it looks like the bet solution to your current build to re-build, with holes in the bucket for a lower screen, vertical screen cuts, 1/8 slot, and a single layer of screen. While you are at it, you have the option of changing to opaque hose.

[nac]

Thanks for the feedback SantaMonica.

The slot currently is 1/8 inch. I removed a screen – and you are absolutely correct that made it a lot quieter. I'm still getting a lot of bubbles in the return.

Another shortcoming I recognized:
I don't have an easy way to turn off the water from the overflow! I really need a valve to be able to turn if off, otherwise every time I clean them the tank will fill with algae.

I already have some starter algae. I cleaned the glass of the tank, which had algae, so when it went down the screen, it got caught. Quite a bit actually.

If I wrap things with foil – I need to use mylar foil, correct? Not aluminum.


Regarding lowering the pipe into the bucket – I'd hate to lower everything a few inches and lose that much screen. I think I will try a combination of lowering the pipe say an inch, and putting a lid of some sort. That would help with evaporation, sound, and allow me to attach the lights better. The lid has handle indents – which can be used like a shelf for the lid. They are almost an inch below the top of the bucket. I'm thinking of making a lid like this:

[attachment=0:10qnmqy4]lid2.gif[/attachment:10qnmqy4]

In order for water to get out of the bucket, it would need to find one of the small seams where the lid meets the bucket (or between lid pieces) and travel up almost an inch.

[nac]

I made a slot in the screen as I illustrated in this pic:
[attachment=0:379lziel]Screen diagram.gif[/attachment:379lziel]

Previously, too much water was escaping out of the end of the slot (farthest from the water source), and as a result it was splashing some. Now with the slot, more water is escaping from the tube earlier, which flows across the middle of the screen. This definitely cut down on noise, splashing and probably bubbles. This was an easy fix compared to increasing the width of the slot.

[nac]

So I cut a second hole in the screen like that diagram, thinking that they help, and if if one helped, two would be better. Wrong. In fact, they are not helping. The water flows out through the hole in the screen, but then splashes straight down into the water causing more bubbles. Making a second hole made it worse. This occurs on the side of the screen I can't really see.

I think the problem is that I'm pushing about 600 gph through a 11" slot which is 1/8 " wide, plus with the screen in the way. The slot simply isn't big enough, and the water is jetting out. I will make the slot wider this weekend. I also raised the water level in the buckets. And lastly, I will make some sort of a bubble trap with PVC pipes.

Microbubbles BE GONE!

On the plus side, Nitrate and Phosphate levels are at zero at last test. No water changes ever, and had fish for 6 weeks now. Algae on the live rock, which was growing like crazy, is starting to slowly subside. The growth on the screen is still pretty dark, I'm cleaning it twice a week. I put both lights on one side of the screen, might add wattage.

[nac]

Ack. I widened the slot. Replaced the screen with a new one and no slots. NO reduction in bubbles. The water is all flowing down the screen, and bubbles are still resulting. Too much water, going too fast down the screen. Not enough area in the bucket / sump to allow bubbles to dissipate. I also don't have a lot of space for a pcv bubble reducer.

My next idea is this:
[attachment=0:325mzzgw]SisterScreens.gif[/attachment:325mzzgw]

Attach two "sister" screens to the main screen, at a point above the water line. I'll sew them on with fishing line. When I put them in the bucket, have them up against the bucket side, forming "U" shapes against the bucket sides. My theory is that when water encounters the sister screens it will immediately slow down - have more to flow around and through, and the angle of the sister screens. Then when it flows below the water line - it will need to go through the screens - again slowing it down and hopefully trapping the bubbles above the sister screens.

I need to buy fishing line and will try my plan this weekend.

If this doesn't work, I'll go the pvc bubble reducer method, but as I said space is a bit tight.
My last resort will be to reduce the flow.

[SantaMonica]

Consider also just having someone build an acrylic box that will fit the area you have. Won't be more than $100.